In silicon on insulator (SOI) technology a thin silicon layer is formed over an insulating layer, such as silicon oxide, which in turn is formed over a bulk substrate. This insulating layer is often referred to as a buried oxide (BOX) layer or simply as a BOX. Sources and drains of field effect transistors (FETs) are formed by the addition of N-type and/or P-type dopant material into the thin silicon layer, with a channel region being disposed between the source and drain.